1. Field of the Invention
The present invention relates to a rotary magnetic disc device and, in particular, to a rotary magnetic disc device which is suitable for use in a magnetic recording/reproducing apparatus in an electronic still camera or the like.
2. Description of the Related Art
Recently, there has been developed an attractive electronic still camera system in which an image pickup device such as a solid image pickup element, an image pickup tube or the like is combined with a recording device employing as a recording medium thereof an inexpensive magnetic disc having a relatively larger storage capacity such that an object can be still photographed electronically and recorded into a rotating magnetic disc and the reproduction of the recorded image can be performed by means of a television system, a printer or the like which is provided separately from the electronic still camera system.
The magnetic disc that is employed in such camera system is usually used in the form of a magnetic disc pack. In the magnetic disc pack there is rotatably stored a magnetic disc which is capable of magnetic recording of still image information or the like, and such magnetic disc pack is used after it is mounted to a rotary magnetic disc device which is incorporated in an electronic camera.
When the magnetic disc pack is mounted to the magnetic recording or reproducing apparatus in the electronic camera, it is troublesome and inconvenient to directly mount or locate a central bore, which is formed in a center core disposed in the central portion of the magnetic disc within the magnetic disc pack, onto a rotary drive shaft which is positioned on the side of the magnetic recording or reproducing apparatus. For this reason, such locating operation may result in the inaccurate mounting of the magnetic disc pack to the magnetic recording or reproducing apparatus.
In order to eliminate the above-mentioned problem, conventionally, there has been proposed a magnetic disc pack loading/unloading device which comprises a cover supported to the main body of the magnetic recording or reproducing apparatus such that it can be freely opened or closed, and a pack holder which can be operated cooperatively with the cover and in which the magnetic disc pack can be stored. That is, in the magnetic disc pack loading/unloading device, by closing the cover after insertion of the magnetic disc pack into the pack holder, a magnetic disc in the magnetic disc pack within the pack holder can be mounted to the rotary drive shaft of the main body of the magnetic recording or reproducing apparatus.
By the way, in the above-mentioned magnetic disc pack loading/unloading device, there is a necessary center core push member which is used to securely mount the center core of the magnetic disc to the rotary drive shaft. The center core push member is adapted such that, when closing the cover, it pushes against the center core of the magnetic disc from above toward the drive shaft and, during the magnetic recording or reproducing operation, it gets detached from the center core of the magnetic disc.
Also, in such magnetic disc pack loading/unloading device, there must be provided a regulation plate which is disposed at a position opposing to a magnetic head and is used to run the magnetic disc along the magnetic head during the magnetic recording or reproducing operation. The regulation plate is located at a position opposed to the magnetic head with the magnetic disc therebetween during the magnetic recording or reproducing operation However, in operations other operations than the magnetic recording or reproducing operation, the regulation plate must be separated from the magnetic head so as to prevent production of any pressure traces on the magnetic disc.
As mentioned above, in the rotary magnetic disc device in accordance with the prior art, there are necessarily a cover lock mechanism, a center core push drive mechanism, a regution plate drive mechanism and the like which need drive sources, respectively. The provision of the respective drive source requires a large space therefor.